Use .infobox iinstead of .maintenance_finished

Signed-off-by: John Rayes <live627@gmail.com>
Use .infobox iinstead of #task_completed
And the relevant CSS

Signed-off-by: John Rayes <live627@gmail.com>
Add icon and a deeper green to .infobox

Signed-off-by: John Rayes <live627@gmail.com>
Merge pull request #841 from live627/maint

Use .infobox more